crosstool-ng/packages/gcc/14.2.0/0016-Revert-one-of-the-force_subreg-changes.patch

From 5468439a1f987b7d801c6c76d6c989e57af8916a Mon Sep 17 00:00:00 2001
From: Richard Sandiford <richard.sandiford@arm.com>
Date: Tue, 25 Jun 2024 09:41:21 +0100
Subject: [PATCH 16/16] Revert one of the force_subreg changes

One of the changes in g:d4047da6a070175aae7121c739d1cad6b08ff4b2
caused a regression in ft32-elf; see:

    https://gcc.gnu.org/pipermail/gcc-patches/2024-June/655418.html

for details.  This change was different from the others in that the
original call was to simplify_subreg rather than simplify_lowpart_subreg.
The old code would therefore go on to do the force_reg for more cases
than the new code would.

gcc/
	* expmed.cc (store_bit_field_using_insv): Revert earlier change
	to use force_subreg instead of simplify_gen_subreg.

(cherry picked from commit b694bf417cdd7d0a4d78e9927bab6bc202b7df6c)
---
 gcc/expmed.cc | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/gcc/expmed.cc b/gcc/expmed.cc
index bd190722de6..85ec2614a3f 100644
--- a/gcc/expmed.cc
+++ b/gcc/expmed.cc
@@ -695,7 +695,13 @@ store_bit_field_using_insv (const extraction_insn *insv, rtx op0,
 	     if we must narrow it, be sure we do it correctly.  */
 
 	  if (GET_MODE_SIZE (value_mode) < GET_MODE_SIZE (op_mode))
-	    tmp = force_subreg (op_mode, value1, value_mode, 0);
+	    {
+	      tmp = simplify_subreg (op_mode, value1, value_mode, 0);
+	      if (! tmp)
+		tmp = simplify_gen_subreg (op_mode,
+					   force_reg (value_mode, value1),
+					   value_mode, 0);
+	    }
 	  else
 	    {
 	      tmp = gen_lowpart_if_possible (op_mode, value1);
-- 
2.44.2